1. Field of the Invention
The present invention relates to a closed type sprinkler head, connected with a fire extinguishing piping, for containing compressed fire extinguishing water filled in the fire extinguishing piping in the ordinary time, and discharging the compressed and supplied fire extinguishing water at the time of a fire.
2. Description of the Related Art
In the conventional sprinkler fire extinguishing equipment, a stemmed piping stemmed from a water supply piping for supplying fire extinguishing water is provided in the ceiling of a room, which is a protected section in a building. A sprinkler head is connected with the tip part of the fire extinguishing piping elongating from the stemmed piping in the state exposed inside the room via the ceiling surface.
The sprinkler head contains the fire extinguishing water to be compressed and supplied from the fire extinguishing piping by maintaining a valve body in the closed state by a heat sensitive operation mechanism, and the like, when there is no fire. When a fire breaks out, the valve body is opened by melting the fusible alloy provided in the heat sensitive operation mechanism so that the fire extinguishing water compressed and supplied from the fire extinguishing piping can be discharged.
According to the sprinkler head, a sealing member needs to be provided in the valve body for improving the closeness in containing the fire extinguishing water by the valve body when there is no fire. In a conventional sprinkler head, a copper sealing member has been used for the sealing member, however, since the copper sealing member has a low elasticity, it is required to apply a large load onto the sealing member for improving the sealing property so as to enhance the close contact with the valve body. Furthermore, a problem is involved in that a strength sufficient for enduring the sealing load is required in the parts where the load is to be applied, such as the heat sensitive operation mechanism, and the like, because a large load needs to be applied. Besides, it is also problematic that a copper sealing member can easily corrode.
As a method for solving the problems, a sprinkler head according to Japanese Unexamined Utility Model Publication No. 163552/1989 shown in FIG. 4 comprises a sealing member 113 of a valve body 104 made from a fluorine resin so as to maintain the sealing property, the anti-corrosion property, and the weathering resistance with a smaller load with respect to a conventional metal packing.
Furthermore, in order to solve the problem of the copper sealing member, a sprinkler head according to the official gazette of Japanese Examined Utility Model Publication No. 36677/1995 shown in FIG. 5 comprises an O ring 214 made from a fluorine resin as the sealing member for a valve body 215 such that the O ring 214 keeps the sealing property by the surface contact with O ring storing grooves 213, 216a.
As another method for solving the problems, the use of a rubber O ring in place of a copper sealing member is conceivable, however, since a rubber O ring may be altered by a long term use so as to adhere onto the valve body or the water discharging opening end part to disturb the smooth operation, or generate sealing leakage, a fluorine resin O ring 214 is used in the above-mentioned second prior arts.
However, according to the sprinkler head with a fluorine resin sealing member in place of a copper sealing member shown in FIG. 4, since a fluorine resin does not have an elasticity as much as a rubber, still a comparatively large assembly load needs to be applied onto the sealing member in order to improve the sealing property. Besides, a problem is involved in that a strength sufficient for enduring the sealing load is required in the heat sensitive operation mechanism.
Similarly, according to the sprinkler head with a fluorine resin O ring shown in FIG. 5, since a fluorine resin does not have an elasticity like a rubber, a sufficient sealing property cannot be obtained by the deformation of the fluorine resin O ring 214 by the hydraulic pressure of the compressed fire extinguishing water from the water discharging opening 211 contained by the valve body 215. Therefore, a problem is involved in that a strength sufficient for enduring the sealing load is required in the heat sensitive operation mechanism because a comparatively large assembly load needs to be applied onto the sealing member 214 by the assembly of the heat sensitive operation mechanism.